Bug#448775: Uses too much entropy (Debian Bug #343085)

Andreas Metzler ametzler at downhill.at.eu.org
Sat Mar 8 09:48:18 CET 2008

On 2008-01-31 Werner Koch <wk at gnupg.org> wrote:
> On Wed, 30 Jan 2008 19:20, ametzler at downhill.at.eu.org said:

>> Any obvious breakage? Exim does not use any threading. I have not
>> included an gcry_check_version(NULL) since I thought gcry_control()
>> would fail as reliably as gcry_check_version() would, if gcrypt was

> Better insert a gcry_check_version because this is the safe way to
> initialize gcrypt.  The initialization is also done with most other
> gcry_control calls but that is a failsafe feature.  Explicitly
> initialization is better (you don't need to check the return code, just
> call it.)


we still seem have not been able to find a really working solution,
this patch <http://svn.debian.org/wsvn/pkg-exim4/exim/trunk/debian/patches/65_saverandomseed.dpatch?op=file&rev=0&sc=0>
causes crashes in exim.

Quoting Marc Haber in http://bugs.exim.org/show_bug.cgi?id=654
| However, the secondary MX (which delivers some spam to the primary MX) noted
| that the primary box had become unreliable in TLS:
| 2008-01-30 14:51:21 1JKDKT-0003ME-AG Remote host mailgate.zugschlus.de
| [] closed connection in response to STARTTLS
| When this happened (a couple of times per hour), I didn't get any
| atypical log entries on mailgate.
| This was a repeating, but intermittent failure since mailgate
| continued to work normally, and STARTTLS was successful most of the
| time.
| Going back to the same exim sans the random-seed patch, entropy
| average went back to 200, but the STARTTLS failures vanished.

We have tried to isolate what actually breaks, by only applying parts
of the patch (e.g setting up dthe seed file, but not updating it.),
but it looks like the mere presence of
gcry_control (GCRYCTL_SET_RANDOM_SEED_FILE,filename)
causes the crashes.

I am really wondering whether using the experimental daemon might be
worthwile, there does not seem to be much cost involved, and
/dev/(u)random has not got any policy controls either.
cu andreas
`What a good friend you are to him, Dr. Maturin. His other friends are
so grateful to you.'
`I sew his ears on from time to time, sure'

More information about the Gcrypt-devel mailing list